A coordinated multi-point (CoMP) transmission technology is introduced in a long term evolution (LTE) communication system, so as to improve the spectral efficiency of the system and the performance of a cell edge user. As the number of users in the communication system using the CoMP technology increases, it has been difficult for the existing physical downlink control channel (PDCCH) resource which is used for transmitting user scheduling indication information to meet the requirement of scheduling users, and therefore, an enhanced-physical downlink control channel (E-PDCCH) resource is further defined on the time-frequency resource, the E-PDCCH resource occupies a part of the existing physical downlink shared channel (PDSCH) resource, and frequency division multiplexing (FDM) is adopted between the E-PDCCH resource and the PDSCH resource to share the time-frequency resources.
Since the E-PDCCH multiplexes a part of the PDSCH resource, the user equipment (UE) adopts a same demodulation manner with the PDSCH, namely, demodulating the E-PDCCH with a demodulation reference signal (DMRS). The UE needs to generate an initial value of DMRS when obtaining the DMRS in each time slot, and the generation of the initial value of DMRS relates to three parameters, including a time slot number, a scrambling code ID notified by a base station, and an initial ID of DMRS which is selected by a network side from a candidate ID set and used for transmitting in the present time slot. Among the above three parameters, the scrambling code ID and the initial ID of DMRS need to be transmitted via the E-PDCCH, however, the parameter for calculating the DMRS is obtained by demodulating the E-PDCCH, and demodulating the E-PDCCH also needs the DMRS, therefore, according to the existing manner, it is difficult for the UE to obtain the DMRS for the control channel E-PDCCH, and thus it is not possible to demodulate the E-PDCCH for obtaining scheduling indication information.